Telephone apparatus and system.



No. 684,60l. Patented Oct. l5, l90l.

F. B. COOK.

TELEPHONE APPARATUS AND SYSTEM.

(Application filed. Apr. 13, 1898.

-2 Sheets-Sheet I:

(No Model.)

QUWWww PETERS co, Mom-Lima, msummon n c UNITED STATES PATENT OFFICE.

FRANK B. COOK, OF CHICAGO, ILLINOIS.

TELEPHONE APPARATUS AND SYSTEM.

SPECIFICATIQN forming part of Letters Patent No. 684,601, dated October 1901- Application-filed April 13, 1898. Serial No. 677,421. (No model.)

To all whom it may concern:

Be it known that I, FRANK B. COOK, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Telephone Apparatus and Systems, of which the followingis a specification.

My invention relates to certain improvements in the circuit arrangement and apparatus employed in connection with telephone systems. At the stations of the subscribers and at the centralstation or exchange of such a system apparatus is employed by which to generate a current of electricity to be employed for extending a signal from the subscriber to the central station or exchange and from the central station or exchange to the subscribers station. Itis frequently the case that the wiresoffa telephone system exterior to the subscribers station and the central station or exchange become crossed or connected with the wires of other systems carryingheavy and strong currents of electricity. This cross or connection frequently causes damage and injury to the apparatus and also to the persons at the subscribers station and at the central station.

The object of my invention in one particular is to employ means in the circuit whereby the generating apparatus for the extension of signaling-currents is isolated and separated from the circuit with which it is adapted to be included, avoiding the danger to the apparatus and person usually incident to systems of this character.

In connection with telephone systems it is customary to include a plurality of subscribers stations upon one telephone-circuit, and under such circumstances such a circuit is called a party-line or party-circuit.

In the ordinary operation of the telephoneexchange metallic conducting-plugs connected by cords are employed to connect the different subscribers lines together at the switchboard by the insertion of the plugs in the respective switches of the subscribers on the switchboard. When a subscriber extends a call to the central station, the operator inserts one of these plugs in the switch of that subscriber and after ascertaining the number of the subscriber with whom connection is desired she then inserts the other one of the plugs in the'switch of the subscriber to be called and by means of a ringing-key extends a signal to that subscriber. In connection with the party-line-circuit arrangement beforesaid it has heretofore been customary to employ a different ringing-key for each one of the several subscribers on the same party-line circuit. Thus, for instance, in a party-line having four subscribers included in a circuit there would be at the central station four ringing-keys for each pair of cords, whereby a ringing-key is provided for each of the four subscribers. Such an arrangement multiplies the apparatus and requires correct skill and more exertion on the part of the operator to extend the signals correctly and rapidly to each proper subscriber.

Myin vention, in connection with party-line circuit, is designed to overcome the present existing circuit arrangement and apparatus used in connection with the party'linecircuit and to provide a circuit arrangement and apparatus which is simple in character and calculated to provide means whereby connections may be rapidly and properly made at all times.

My invention has certain other objects in view; and it consists in certain features about to be described, reference to be now had to the accompanying drawings, in Which Figure l is a diagrammatic view illustrating the circuit arrangement and apparatus whereby the generator at the subscribers stations is isolated from the line-circuit. Fig. 2 is an end viewof the generator, which shows the construction of the device whereby the generator when rotated operates to include itself in circuit with the line. Fig. 3 is an enlarged detail view on the line a a of Fig. 2. Fig. 4 is a like view on the line'b Z) of Fig. 2. Fig. 5 is a diagrammatic View illustrating the circuit arrangement of a party-line circuit having four subscribers included therein. Fig. 6 is a diagrammatic View of the circuit arrangement and apparatus of the party-line system at a central station in series. Fig. 7 is a like view of a modified form. Fig. 8 is an enlarged detail View of a portion of a spring-jack and plug adapted for use in connection with more particularly the arrangement shown in Fig. 7. Fig. 9 is a like View of a party-line shown in parallel or what may be termed a bridging system.

The apparatus employed at the subscribers stations and at the central station for generating currents of electricity whereby to extend signals is what are known as magnetogenerators, the armature of which is manually rotated by the subscriber, and at central stat-ions a powergenerator is employed, the armature of which is rotated by any suitable means. My invention more particularly, as illustrated, relates to the isolation of the hand-generator of the subscriber from the line-circuit with which it is adapted to be included.

Referring to Figs. 1 t0 4, inclusive, the circuit arrangement and apparatus is disclosed in the illustration for accomplishing the foregoing results, and I will now proceed with a description of the same.

Referring to Fig. 1, it will be observed that the armature 15 of the magneto-generator at the subscribers station is included in a circuit 16, which circuit is uniformly closed through the contact-point 17, said circuit consisting of the spring-strips 18 and 19, adapted to be brought into contact with the springstrips 20 and 21 of the leads 22 and 23 of the line-circuit. It will be observed that these leads 22 and 23 of the line are normally closed through the contact 24, and thus the signalbell A and'the telephone set E are in series with the line. By means to be described in the rotation of the armature 15 of the magneto-generator the spring-strips 18 and 19 are separated, breaking the contact at 17 and bringing said strips against the spring-strips 20 and 21 of the line-leads 22 and 23 and also further separating the said contact-strips of the line to break the circuit at 24. When this is accomplished, it is evident that the normally-established independent generator-circuit 16 is broken and the generator-armature 15 included in circuit with the line. It will be understood, of course, that the telephone is removed from its hook-support when calling.

By reference to Figs. 2, 3, and 4 the means for accomplishing the foregoing result will be observed, consisting of a friction-wheel 25, mounted upon the end of the generator-armature shaft 26, which frictionwheel bears against a loose contact-making roller 27, of

insulating material, upon which rests the contact spring-strips 18 and 19. Located above the contact-springs 18 19 are the line contact-strips 20 and 21. The springs 18 and 19 normally rest upon the contact-plate 17, Fig. 4, and the springs 20 and 21 normally rest upon the contact-plate 24, Fig. 3. By this means the circuits are closed or completed through the plates, the circuit of the contactsprings 20 and 21 being closed through ,the plate 24 and the circuit of the contact-springs 18 and 19 being closed through the plate 17. \Vhen the armature 15 of the generator is 1'0- tated in the proper direction, the frictionwheel 25 is also rotated in the direction of the arrow, Fig. 2, and by virtue ofits peripheral frictional contact with the roller 27 causes the latter to travel upwardly and press upon the spring-strips 18 and 19, thereby separating the contact between said strips by removing them from the contact-plate 17, thus breaking the short circuit about the generator and bringing them into contact with the line spring-strips 20 and 21. In the further upward travel of the roller 27 the continued upward pressure of the spring-strips 18 and 19 upon the line-strips 20 and 21 lifts these strips from off the plate 24, thereby opening the line-circuit. By this arrangement of the circuit and apparatus it will be observed that the generator is completely isolated and separated from the line. A normally-closed local circuit is provided around the generator, by which it is protected against injury of strong currents and those persons using the apparatus also protected. The entirely-disconnected closed local circuit affords a double protection in the separation of the generator entirely from the line and a local circuit about the generator. It is evident that the generator is isolated completely when not in operation for signaling purposes. In such a case should any person touch the conducting portions of the generator no shock or injury can result because of such separa= tion and isolation of the generator from the line should the line he charged with a dangerous current from any cause. Should a current in one branch of the line-circuit bridge the gaps to the other branch of the line-cir-' cuit when the generator is not in use, this current would find a closed path through the contact 17 instead of through the windings of the generator-armature.

Referring to Fig. 5, I have shown an arrangement by which this method is applicable to what is known as party-lines. In this arrangement the calling-bells Aare included in a branch circuit permanently between the ground and the line and the magneto-generator and telephone set are bridged across the line when in use, the leads 22 and 23 of which form a metallic circuit for talking purposes. It will be understood that the telephone is removed from its hook-support while talking. It will be observed also that in this instance the generature-armature 15 is included nor mally in the independent circuit, as in the previous instance described, and adapted to be included in circuit with the line by rotation of the armature. In this instance, however, when the contact 24 is broken one of the line contact-springs 20 is brought against the ground-contact 28. This result is accomplished in the still further upward movement of the roller 26. I have shown four callingbells, two of which are arranged on each of the leads 22 and 23, whereby it becomes necessary to use only one of said leads when the central office signals either set of calling-bells. The calling-bells of each lead are constructed IIO to respond to currents of different polarity, and thus when it is desired to call any one of the two on one line it is simply necessary to send out an impulse of a polarity to which the desired bell will respond. It is evident that the same result will be obtained with the other bells on the other lead of the circuit. In order to signal the central office from any given station without disturbing any other station, the armature in its rotation establishes the ground-contact 28 with the contactspring 20, thereby grounding the lead 22, which prevents the signal-bells attached to that lead from responding. The signal-bell of the station extending the call will respond; but the remaining bell, connected with the lead 23, is arranged to be unresponsive to the polarity of current from the calling-station. The drop D of the central station will respond to a current of either polarity. In order to generate a current of one polarity, any one of the various Well-known means may be employed. Thus an ordinary generator with a suitable commutator and brushes may be employed, whereby a straight current is produced, or one side of the collector-ring may be insulated, so that one pulsation of the alternating current only is utilized, thus pro ducing a pulsating current of one polarity.

In Fig. 6 I have shown a series arrangement for a party-line circuit whereby to dispense with ringing-keys and accomplish other desirable results. In connection with this arrangement I employ the usual cords and plugs for connecting subscribers lines together.

I have shown in Fig. 6 acircuit havingfour subscribers stations J J and J J thereon two on each lead 29 and 30. The leads 29 and 30 are extended to the first one of series of spring-jacks K, and each of the springjacks are electrically connected together and to generators L and L in a manner to be described. The last one of the series of springjacks L has connected electrically to it the annunciator M, which responds as a signal from any one of the subscribers stations. The line 29 of the exterior circuit is connected to the sleeve of the first one of the series of jacks K, and the sleeve of this jack is also connected by the wire 31 with the spring-contact 32 of the second jack, and the sleeve of this jack is likewise connected by the wire 33 with the spring-strip 32 of the third jack, and the sleeve of this third jack is connected with the spring-contact bymeans of the wire 34. The lead 30 is connected with the springcontact 32 of the first jack, and the wire 35 connects a contact-point 36 of that jack with the spring-contact 32 of the third jack. The wire 37 connects the contact-point 36 of the second jack with the spring-contact 32 of the last jack, and the contact-point 36 of the third jack is connected to the sleeve of the last jack, the contact-point 36 of which latter is connected to the same sleeve through the annunciator M. The generator L is connected to the generator spring-contacts 39 of the first and second jacks and the generator L is connected with the generator spring-contacts 39 of the third and last jack. The minus side of the generator L is connected to the ground N, and the plus side of the generator L is connected to the ground N.

I will now proceed to describe the manner in which this system is operated. Assume that the subscriberat some onestation extends a call to the central station. The signalingcurrent will pass through the coils of the'annunciator M and operate the same to indicate a signal. The operator not knowing which subscriber has called inserts a plug in any one of the spring-jacks, and as all of the jacks are connected to the leads 29 and 30 the operator may inquire the number of the subscriber extending the call and also obtain the number of the subscriber with which connection is desired. If the plug is not in the jack of the subscriber extending the call, the operator removes it from the jack in which it has been inserted and inserts itinto the jack of the calling subscriber. Having ascertained the number of the subscriber with which connection is desired,the operator then inserts the other plug of the pairinto thejack of the called subscriber and, inserting it to its farthest extent,causes the tip of the plug to engage the insulating-abutment and force the line contact-spring 3.2 into contact with the generatorstrip 39 and by so doing connects the line with the generator-strip to signal the subscriber with which connection is desired. Suppose, for instance, that the station J extends a signal to the central office and desires connection with the station J As both of these stations are on the same side of the metallic circuit, it is necessary to provide means for sending a selective current in order to prevent the extension of a signal to both subscribers when it is desired, of course, to signal but one. This is accomplished by virtue of the connection with the two generators, so that the plus side of one generator is connected to the jack of one station and the minus side of the other generator to the other jack. As shown, the station J responds to the current from the generator L, and the station J responds to the current from the generator L The plug being in the third jack, which is correspondent to the station J the minus current of the generator L is sent out over the line 29 to the station J the bells of which respond to said current. When the signal has been extended by forcing the line-strip 32 upon the generator-strip 39 in the manner described, the plug is automatically retracted and resumes the initial position.

In Fig. 9 I have shown the means employed in one form for forcing the line-strip 32 into contact with the generator-strip 39, consisting of the two insulating-pieces and 51, both of which are movable and pivoted together at 52. The lower piece 50 rests upon the sleeve of the plug and at its base is held from rearward movement by the abutment 53, andthe piece 51 is pivoted to the line-strip 32. Thus as the tip of the plug presses against the two pieces 50 and 51 where they are piv-' oted together the line-strip is forced upon the generator-strip and the connection between the plug and the line-strip severed.

It is obvious that the form of construction shown in Fig. 9 may be employed or that illustrated in Fig. 7, and whereas with the form as shown inFig. 9 the plug is restored to its initial position by the readjustment of the parts 50 and 51 under the influence of the spring-strip 32, with the form shown in Fig. 7 a spring or other suitable construction may be utilized to accomplish this restoration, whereby the connection between the line and generator is severed and that between the line and the plug reestablished. It is further obvious that signals may be extended and connections established between the stations on the line or lead 30 in the same manner as described and likewise between stations located the one on the lead 29 and the other on the lead 30.

In Fig. 8 is shown a circuit arrangement by which one generator may be employed at the central station instead of two. In this arrangement the line-strip 32 is forced by the plug against a supplemental generatorstrip 60, insulated from the generator-strip (51. This supplemental strip is connected with a like strip in the next one of the series of spring-jacks by a wire 62. The generator-strip of one jack is connected by the wire 62 with the supplemental generator-strip of the next jack, and the generator N is bridged across between said wires 61 and 62. Upon inserting a plug into the jack the first in the series and forcing the line-strip against the supplemental strip the generator-strip connected with the wire 62, leading to the plus side of the generator, is forced onto the ground-contact 63, and thus connected with the ground at N The course of the current is therefore from the plus side of the generator N to the generator-strip 39 and thence through contact 63 to the ground N The plus side of the generator is therefore connected to the ground. The course of the current from the minus side of the generator is through the wire 61 to the, supplemental strip 60, from thence -to the line-strip 32 in contact therewith to the line 30, whereby the minus-bell of the station J therein is operated to give a signal, while the plus-bell of the station J of the same branch or circuit is unresponsive to the minus-current. To ring out on the second jack of the series to the station J a plug is inserted in said jack and the generatorstrip forced onto the ground N and the linestrip 32 brought into contact with the supplemental strip 60. Bythis means the minus side of the generator is grounded and the plus side connected with the line 30, whereby the plus-bell of the station J 3 may give a signal, while the minus-bell of the station I is unresponsive.

For the sake of clearness I have only illustrated two jacks and means for operating the two bells J and J on one side or branch of the metallic circuit; but it is evident that the bells J and J on the other branch are operated by like jacks and connected apparatus.

In all of the circuit arrangements heretofore described the central-office drop or annunciator may be cut out by being left in a normally open branch, but in Fig. 9 is shown a circuit arrangement by which the centraloffice drop (designated at M) may be shunted out of the circuit. This is accomplished by providing a spring-jack having the contactsprings and 81, the drop M being located in a branch 82, connected to the contactspring 81 and one of the leads 83 of the linecircuit. When a plug is inserted which contacts with the spring 81, the latter is raised and brought into contact with the spring 80, and the circuit is therefore from the top of the plug to spring 81, to spring 80, to line 83, thus shunting out the drop M. Normally when this plug is not in the jack the circuit is from the lead 83, through the brush 82 and drop M, to the spring 81 of the first jack, which is connected by lead 84 to the contact spring 81 of the second jack, which latter'is connected to the other lead 85 of the linecircuit. In all of these forms contained in Figs. 7, S, and 10 differential signals maybe given at the several stations on one branch or on one circuit whereby a signal may be given at one station on one line without extending a signal to the other station on the same line. Under the circumstances, as shown in Fig. 7, when a signal is being extended over one line the other line leading to the stations is cut out.

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is-

1. In a metallic-circuit party-line system a plurality of sets of signaling devices each of which responds to a current of a given polarity and connected between one of the'leads and the earth, and means associated with each said device for putting a direct ground on one side of the circuit to prevent the signal devices on that side from operation, together with a generator capable of generating a current of such polarity that the othersig- ICO nal devices on the same side of the circuit circuit of a supplemental or branch circuit including the telephone set and calling apparatus, the limbs of which are respectively connected with the limbs of the main circuit, a ground branch at said set and normally disconnected, and means for connecting said ground branch With the metallic circuit when calling.

4. In a metallic-circuit party-line system the combination with the main circuit of a supplemental or branch circuit, including the telephone set and calling apparatus, the limbs of which are respectively connected with the limbs of the main circuit, a ground branch at said set and normally disconnected, and means for connecting it with the metallic circuit when calling, together with signal-indicators responding to currents of dilferent polarity and normally connected between each limb of the metallic circuit and the ground.

5. In a metallic-circuit telephone-line having a plurality of substations, a central-office signal in the line, a grounded signal at each substation connected with one conductor of the line and responsive to a particular character of current, a normally disconnected ground branch at each substation for the other conductor of the line, a generator also at each substation capable of generating only current of the character to which its associated signal responds, and means to connect said generator in the line and the ground branch to its conductor, whereby when the generator is operated only that substations signal and the central-office signal are operated.

6. In a metallic-circuit telephone-line having a plurality of substations, a central-office signal in the line, a grounded signal at each substation connected with one conductor of the line and responsive to a current of given polarity, a normallydisconnected ground branch at each substation for the other conductor of the line, a generator also at each substation capable of generating only current of the polarity to which its associated signal responds, and means to connect said generator in the line and the ground branch to its conductor, whereby When the generator is operated only that substations signal and the central-office signal are operated.

7. In a metallic-circuit telephone-line having a plurality of substations, a central-office signal in the line, a grounded signal at each substation connected with one conductor of the line and responsive to a particular character of current, a normallydisconnected ground branch at each substation for the other conductor of the line, a generator also at each substation capable of generating only current of the character to which its associated signal responds, and means to automatically connect said generator in the line and the ground branch to its conductor in the operation of the generator for calling purposes.

8. In a metalliccircuit telephone-line havin g a plurality of substations, a central-office signal in the line, a grounded signal at each substation connected with one conductor of the line and responsive to a current of given polarity, a normally disconnected ground branch at each substation for the other conductor of the line, a magneto-generator also at each substation capable of generating only current of the polarity to which its associated signal responds, and means operated by the driving mechanism of the magneto to connect said magneto in line and said ground branch to its conductor.

9. In a signaling system, a metallic line having a signaling device therein, a ground branch from each side of the line containing a signaling device, an additional ground branch associated With one of said grounded signaling devices, a generator also associated therewith, and means to connect said generator into circuit and the additional ground branch to the other side of the line from the said signaling device, whereby when the generator is operated the signal device connected with the side of the line grounded by the additional branch is not operated.

10. A magneto call apparatus, consisting of a generator, the armature of which is in a normally-closed local circuit entirely disconnected from the main circuit, and means for opening the said normally-closed independent local circuit, and including the said local circuit as a part of the main circuit.

11. In a magneto call apparatus, the combination with a main line, a magneto-generator, a normally-closed independent local circuit including the said generator, and means for automatically breaking said local circuit and connecting the generator into the main line in the operation of the generator.

12. In a call apparatus, the combination with a main line, a local circuit entirely disconnected and independent of the main line, a magneto-generator having its armature in the said local circuit, and means operated by the crank of the magneto for breaking said local circuit and connecting the generator with the main line.

13. In a substation call apparatus, a main line having contacts normally in electrical connection, an independent local circuit also having contacts normally in electrical con,- nection and adjacent the main-line contacts, a magneto-generator having its armature included in said local circuit, and means automatically operated by the generator to break the connection between both sets ofcontacts and force the local-circuit contacts into connection with the main-line contacts to include the generator and local circuit in the main line.

14. In a partyline telephone system, a plurality of subscribers stations on the partyline, spring-jacks at the central station, one for each subscribers station, a generator having terminals permanently associated with the jacks to extend relatively, differential current to each subscribers station, when brought into circuit therewith, and'means for connecting said terminals With the linecircuit in the act of inserting the plug into the jack.

15. In a party-line telephone system, the combination with the line circuit or circuits, having a plurality of subscribers" stations thereon of spring-jacks at the central station, one for each of the subscribers stations of the party-line, a signaling-generator one side of which is connected to the ground and the other side having terminals permanently associated with the jacks and adapted to be connected to the line to transmit a signalingeurrent of one character to one station on the line and thereby signal said station, and another generator reversely connected in a similar manner to the ground and adapted to be similarly connected to the jacks and line to transmit a current of another character to another station on the same line to signal said station while the signaling apparatus of the other station is unresponsive.

terminals permanently associated with the spring-jacks and means for connecting alternately opposite sides of the generator to- 'groundor a common return and to the line through the said terminals.

17. In a spring-jack for telephone systems a jointed lever disposed between the body of the jack and one of the line-springs, to be engaged by the plug to move theline-springs. In testimony whereof I affix my signature in presence of two Witnesses.

FRANK 'B. COOK. Witnesses:

CHAS. G. BULKLEY, L. M. BULKLEY. 

